San Francisco's Outside Lands is no longer the eager upstart of the summer festival circuit - with this year's impressive lineup, it's now a seasoned veteran.

If you're looking to beat the heat but still see great music, San Francisco is your festival city. Between Treasure Island, Outside Lands, and even the free Hardly Strictly Bluegrass Festival (which will feature such decidedly non-bluegrass names as Low, Sonny and the Sunsets, and MC Hammer this year), this City by the Bay draws tons of talent - without tons of booty shorts.

With its all-star lineups, killer food options, and quirky vibe, Outside Lands is easily the pinnacle of this festival scene. An endlessly foggy Golden Gate Park gets transformed into a microcosm of the surrounding city: it becomes a hodgepodge of gourmet food stands, hippie enclaves, decked-out tech tents, and hipster havens. Now in its sixth year, the event is a must for both locals and music-loving tourists looking to experience the Bay in a handy three-day burst.

This year's event was as quintessentially SF as any of its previous five ventures, but it also had something else: a Beatle.

No, seriously. For a festival that usually features a sparkling lower lineup, this year dominated above the fold. Besides a certain British knight, Outside Lands also saw Nine Inch Nails, The National, Yeah Yeah Yeahs, Vampire Weekend, and more on its four main stages. The event has always had plenty of heavyweights (we're looking at you, Stevie Wonder and Radiohead), but this year was the first time Outside Lands felt like a Bonnaroo or a Lollapalooza.

Though Outside Lands has expanded every year, this year the festival felt crystalized. They know we'll all flock to Chocolands; the dance-tastic Heineken Dome will be packed to the brims; the Barbary will include increasingly impressive comedy acts, like Craig Robinson, Maria Bamford, and Wyatt Cenac. Outside Lands is still growing, but now they've got the rhythm down pat. It's no longer the eager upstart of the summer festival world--it's the seasoned veteran.

In that sense, Paul McCartney's performance felt symbolic, even more so than Stevie Wonder's the year before. The 71-year-old 'Cute Beatle' blew us away with his three-hour-plus set; there aren't even words to express the surreal joy of hearing classics like 'Yesterday' or 'Hey Jude' live. Of seeing two fireworks displays light up the sky. Of hearing personal stories from McCartney's past, or his poignant tributes to John and George. His set was the clear highlight of the weekend. Despite a perfectly solid lineup, nothing could touch Sir Paul.

Sure, festival-goers got a great mix of era-spanning idols (Hall and Oates, Willie Nelson), modern favourites (Grizzly Bear, Matt & Kim, Phoenix) and rising stars (Jessie Ware, Rhye, MS MR). But for the most part, everything went off like clockwork. There were no lowlights (not by a long shot), but there were also few true standouts. We expected a barrage of top-notch music, and that's exactly what we got: three days of masterful festival mainstays.

This is by no means a bad thing. Outside Lands 2013 provided a brilliant festival experience, and I was able to check numerous bands off my musical bucket list. Everyone should have the chance to catch Karen O in her natural element, rocking out on stage with true star swagger. I was thrilled to catch Nine Inch Nails and Phoenix in the space of one evening, and entering the Polo Fields to the echoes of Foals started my Sunday with a bang. The only thing that leaves me a bit wistful about this year's festival (besides the usual "why hasn't time travel been invented yet" scheduling dilemmas) was the lack of surprise. The bands I knew would be excellent were, and there weren't many shockers - for good or bad.

Outside Lands is such a unique experience in terms of its presentation and offerings. As it becomes an even bigger presence in the summer festival circuit, I only hope that it maintains its individuality and doesn't sacrifice quirk for street cred.